A father shot dead his girlfriend and her two children before setting their home on fire, authorities have said.

Corey LaValley, 32, was arrested on Tuesday for the murders of 33-year-old Debra Sheppard, his 10-year-old son Corey LaValley Jr., and Sheppard's daughter, 13-year-old Emma McComber.

He is accused of shooting the trio dead at their mobile home in Dorr, Michigan on Monday before returning to the home and setting it alight on Tuesday at around 1pm.

Police found LaValley at a relative's home later that evening and took him into custody without incident. He has been charged with open murder, arson and using a firearm during a felony.

'Killer': Corey LaValley, left, allegedly shot dead his girlfriend Debra Sheppard, right, and her two children on Monday before returning to their Michigan mobile home on Tuesday and setting it alight

Murdered: LaValley allegedly killed his 10-year-old son, Corey Jr, left, and his girlfriend's 13-year-old daughter, Emma McComber, from a previous relationship. Her dad said he had feared for his daughter's safety

LaValley was being held by the Allegan County sheriff's office. On Thursday afternoon, he was arraigned via video link.

'We did receive information that for us established probable cause that Corey LaValley, who is the father of one of the people we believe to be deceased, was involved in ultimately the criminal act that caused this,' Allegan County Undersheriff Frank Baker told Fox17 on Wednesday.

Police told the channel that LaValley and Sheppard had been in a relationship, and neighbors told Newschannel 3 that they would often hear the couple arguing.

Authorities have not released a motive for the murders but family members said LaValley had a history of violence. Records show he also had a history of arrests dating back to 2001.